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

Annotations declare openWorldHint=true (external recipients) and destructiveHint=false. The description adds genuinely useful behavioral context the annotations don't cover: it reaches other people so the user should be confirmed before each call, confirmation can be toggled off, and it requires a Cotlet API key with app access.

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 opening two sentences are near-verbatim duplicates ('Email an estimate... for online approval and e-signature' / 'Emails the estimate to the recipients for online approval and e-signature'). Content is otherwise front-loaded and appropriately sized, but the redundancy is avoidable waste.

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?

For a 3-param, fully documented tool with no output schema, the description supplies the missing operational context: auth requirements, external-recipient implications, and confirmation behavior. Complete enough to invoke correctly, with only sibling differentiation missing.

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 'to' (default: project customer), 'message', and 'estimate_id' are already documented. The description's only parameter claim, 'Without recipients it goes to the project customer,' merely restates the schema's default, adding no new semantics.

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 precise verb+resource ('Email an estimate to the client') with the purpose (online approval and e-signature), cleanly separating it from sibling create_estimate/list_estimates. An agent knows exactly what the tool does without opening the schema.

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 contextual guidance: recipients default to the project customer, and the user-confirmation behavior is mentioned. However it never names or contrasts alternatives such as send_change_order or create_estimate, so the when-to-use-this-vs-siblings decision is left to inference.

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