search_messages

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds a meaningful behavioral trait beyond those flags: that results can expose sensitive content and should be narrowed via filters to reduce disclosure. That is real added context, though nothing is said about result volume or matching behavior.

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?

A single compact sentence with the action front-loaded and the privacy guidance trailing it. Nothing is wasted, though it is terse enough that a small amount of additional clarification could have been justified.

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?

An output schema exists, so return values need not be described. However, for a four-parameter search tool with zero schema descriptions, the definition leaves the core query syntax and limit semantics unexplained, which is a meaningful gap for correct invocation.

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 burden falls on the description, which only addresses two of four parameters (person/recipient and platform filters). The required 'query' parameter and the 'limit' parameter are never explained, leaving matching semantics and pagination behavior undocumented.

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?

States a specific verb+resource ('Search owner's messages'), which is clear enough to distinguish it from the sibling tools, all of which deal with style profiles, personas, or writing context rather than message retrieval. No explicit sibling differentiation is given, but the domain is unambiguous.

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 clause 'use recipient/platform filters to minimize disclosure' implies a usage pattern (narrow the search to protect privacy), but it never states when to choose this tool over alternatives or when not to use it. Guidance is implied rather than explicit.

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