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

With no annotations, the description carries full behavioral disclosure burden. It only mentions 'full-text search' without addressing pagination, result ordering, case sensitivity, or read-only nature. Critical operational details are absent, making the description insufficient for safe invocation.

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 a single sentence with no redundant words, making it concise and front-loaded. However, it is too sparse to be fully useful, but that is a completeness issue rather than a conciseness one. It earns a high score for efficiency.

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 tool with 5 parameters, no output schema, and no annotations, the description is severely incomplete. It fails to explain result format, pagination behavior, or the meaning of time-range parameters. An agent cannot confidently use this tool without additional assumptions.

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 only 40% (query and chat have descriptions), but the description adds nothing about parameters. The after, before, and limit parameters are undocumented in both schema and description, leaving the agent guessing about their semantics. The description does not compensate for the schema gap.

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 performs full-text search over synced message history, distinguishing it from search_contacts (contact search) and list_messages (listing messages). The verb 'search' plus resource 'message history' is specific and actionable.

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 no guidance on when to use this tool versus siblings like list_messages or get_message_context. It doesn't mention exclusions, prerequisites, or alternatives, leaving the agent to infer usage from the tool name alone.

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