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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds real behavioral context beyond that: the newest-first ordering, that it surfaces older leads a webhook would never have sent, and the auth requirement (Cotlet API key with access to this app).

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?

Dense but front-loaded, leading with what the tool returns and its ordering before secondary notes. Most sentences earn their place, though the list of returned fields and pagination tip crowd the opening.

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?

No output schema exists, yet the description compensates by naming the returned fields (service, location, whether you replied). Combined with auth requirements and pagination, an agent has enough to call it correctly, though the lack of an output schema leaves some detail to inference.

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 coverage is 100%, so the baseline is 3. The description adds some meaning by explaining the cursor round-trip ('Pass next_cursor back as cursor') and the intent of `since`; however it references 'next_cursor', which does not exactly match the schema's 'cursor' parameter name.

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 and resource ('Lists leads in your Thumbtack pro account') and immediately scopes it ('newest first', from the Jobs page). It also names the sibling it is not ('Use get_lead for the customer's full answers'), so an agent can route without opening schemas.

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?

Gives clear usage context ('Filter by creation date to see what came in since your last check') and routes to the alternative tool for detailed lead data. It stops short of explicit when-not conditions, but the practical selection guidance is strong.

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