Search messages

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

No annotations are provided, so the description carries the full burden. It states it returns summaries sorted newest first, which is helpful but omits any disclosure of authentication needs, rate limits, or safety guarantees. The tool is read-only, but the description does not explicitly confirm non-destructiveness.

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 at three short sentences, with no filler or redundant information. Every sentence adds value: function, filtering behavior, and output ordering. It is well-structured and easy to parse quickly.

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?

Given the tool has 9 parameters and no output schema or annotations, the description covers the core functionality and filtering behavior. However, it lacks mention of default limits (e.g., limit defaults to 25) or read-only nature, leaving some gaps in completeness for an agent to fully understand expected behavior.

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 100%, so the schema already documents all parameters. The description adds that filters are combined with AND, but this is a minor addition. No extra semantic detail is provided beyond the schema's parameter descriptions.

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 searches a mailbox, which is a specific verb-resource combination. It distinguishes from siblings like get_message or list_mailboxes by focusing on search with filters, and no other sibling tool has search in its name.

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 mentions that all filters are optional and combined with AND, which provides basic usage context. However, it does not explicitly state when to use this tool over alternatives (e.g., get_message for single messages, list_mailboxes for mailbox listing), nor does it provide exclusions or prerequisites.

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