Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It states that records carry no recipient PII and are addressed by opaque ID, which is useful privacy context. However, it does not explicitly state that the operation is read-only (though 'inspect' implies it), nor does it describe potential side effects, response format, or whether it returns a list or a single item. The description is not misleading but leaves several behavioral aspects unspecified.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and front-loaded, beginning with the core action and resource ('Inspect nominal dead letters') before adding context. Both sentences serve a purpose—defining the operation and clarifying the content—and there is no redundant or filler text. It is well-structured and easy to parse quickly, though it could be slightly more explicit about the tool's scope.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple tool with a single parameter and no output schema, the description covers the key aspects: what it does (inspects dead letters), when it applies (after every retry), and a critical privacy characteristic (no PII). It does not explain the return format or pagination, but given the simplicity and the presence of sibling tools that handle related actions, the description is sufficiently complete for an agent to understand its role. The lack of annotations is partially compensated by the description's clarity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema description coverage is 100%, as the only parameter (organization_id) already has a description ('Active organization ID'). The tool description does not add any additional meaning to the parameter beyond what the schema provides. Since the schema fully documents the parameter, a baseline score of 3 is appropriate; the description does not need to repeat it.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's action ('Inspect') and resource ('dead letters'), and adds context ('What ended up here after every retry'). It distinguishes from the sibling 'commsharbor_dead_letter_replay' by implying a read-only inspection rather than a mutation, though it does not explicitly name the alternative. This is specific and unambiguous, but lacks the explicit sibling differentiation seen in higher-scoring examples.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides context about the tool's purpose (dead letters after retries) and a privacy note (no PII), which implies appropriate usage scenarios. However, it does not explicitly state when to use this tool versus alternatives like 'commsharbor_dead_letter_replay' or 'commsharbor_delivery_events'. The guidance is implicit rather than explicit, leaving the agent to infer the distinction.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.