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

Annotations already cover idempotentHint and destructiveHint, and the description adds the 'permanently' nature, idempotency on retries, and shared daily quotas. This goes beyond the annotations by explaining the permanent consequence and the quota sharing with write/sign actions, adding valuable context without contradicting the annotation flags.

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 moderately sized with multiple distinct pieces of information: purpose, idempotency, quotas, and fallback help. It front-loads the main action and then provides supporting details. The 'Lost?' sentence is somewhat tangential but still serves a navigational purpose. Overall, it is efficient and well-ordered, though slightly longer than strictly necessary.

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 single-parameter mutation tool with no output schema, the description covers the key operational aspects: who can use it, what it does, idempotency, and quota constraints. It does not explain return values or error conditions, but the absence of an output schema makes that less critical. The description is sufficient for an agent to correctly invoke the tool in most scenarios.

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?

Schema description coverage is 0%, so the description carries the full burden of explaining the parameter. It does not explicitly mention agreement_id at all, only that it applies to 'an existing agreement.' The parameter's meaning is implied but not stated, and the description does not compensate for the lack of schema documentation. A score of 2 reflects the insufficient guidance for a single integer parameter that needs context.

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 a specific action: 'permanently open an existing agreement to later signers' with the explicit precondition 'As the original author.' This distinguishes the tool from siblings like sign or agree by focusing on the act of opening accession, not signing or creating.

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?

It provides a clear usage context: only the original author can use it, and it is for opening agreements to later signers. It also includes daily quota constraints and a fallback pointer to /api/tools and the front_door tool. However, it does not explicitly name an alternative tool or state 'use this instead of X when...', which would fully clarify selection among siblings.

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