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

Annotations already declare readOnlyHint/destructiveHint=false and openWorldHint, so safety is covered. The description adds genuinely useful context beyond them: the ordering guarantee ('newest first'), the fields returned, and the auth prerequisite ('Needs the user's Cotlet API key with access to this app'), which is a real operational detail not present in the structured fields.

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?

Short overall, but the first sentence is a fragment that duplicates the field list in the second sentence ('client, total, date sent and status' vs 'client, total and whether the estimate was sent'), wasting a line. The auth note is tacked on at the end rather than being integrated.

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?

There is no output schema, and the description does fill that gap by naming the returned fields and ordering. Auth requirements, filters and the send_estimate hand-off are covered; only pagination behavior (limit) is left to the schema, which is acceptable.

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 echoes two of the three parameters (client filter, creation date) with no syntax or format detail beyond what the schema already states, so it neither adds nor detracts meaningfully.

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 (list estimates) plus scope details (newest first, with client, total, sent status) that let an agent distinguish this from create_estimate and send_estimate. The opening fragment 'Estimates with client, total, date sent and status' restates the same content as the next sentence, so the framing is slightly muddled rather than maximally crisp.

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 concrete selection criteria (filter by client or creation date) and routes the agent to the sibling: 'Pass estimate_id to send_estimate.' No explicit when-not-to-use case is given, but the read-only listing purpose and the hand-off to send_estimate are clear enough to guide invocation.

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