search_messages

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

No annotations are provided, so the description carries the disclosure burden. It adds useful behavioral details—query is case-insensitive, page_size controls fetch size while scanning—but it does not state whether the operation is read-only (though implied by 'Search'), how results are returned, or whether all pages are automatically scanned. These gaps leave moderate ambiguity.

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 compact: a one-sentence purpose followed by a short args block with no filler. It is front-loaded with the primary action and structured for easy parsing, with a clear list format.

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?

With no output schema and no annotations, the description should explain return behavior; it does not. The purpose and inputs are clear, but it leaves ambiguity about whether the function returns all matching messages, how pagination is aggregated, and the response shape. For a simple search tool this is a moderate gap.

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%, and the description compensates well by explaining each parameter: space includes a concrete resource-name format example, query defines case-insensitive substring matching against message text, and page_size explains its role in paging. This adds significant meaning beyond the schema's bare titles.

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 uses a specific verb ('Search'), resource ('messages'), and scope ('in a space containing a text substring'). This clearly distinguishes it from siblings like list_messages (which likely lists without substring filtering), send_message, and list_spaces.

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 choose this tool over alternatives, such as explicitly mentioning 'use list_messages to list all messages' or 'use search_messages when you need substring filtering'. The usage context is only implied by the name and description, with no exclusions or sibling comparisons.

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