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

Annotations only declare destructiveHint=true; the description goes well beyond that by disclosing that it writes data, is non-idempotent, will produce duplicate contacts on repeat calls, returns the new code, and maps to POST /v1/contatos.

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?

Three tight sentences, front-loaded with the action, immediately followed by the most consequential behavioral fact (non-idempotent) and the return value. Zero filler.

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, the description supplies the return value ('the new code'), and the schema fully covers the 10 input parameters. Everything needed to call and interpret the result is present.

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 all 10 parameters are already documented in the schema. The description adds no parameter-level meaning (e.g., that tipo accepts multiple kinds, or CPF/CNPJ formatting), so the baseline 3 applies.

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 (create) and resource (contact), names the entity subtypes in parentheses, and is unambiguously the write counterpart to egestor_get_contact and egestor_list_contacts.

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 non-idempotency warning ('calling it twice creates two contacts') gives real usage guidance for a create tool. It stops short of explicitly routing the agent to egestor_list_contacts to check for duplicates first, which is the natural alternative for a non-idempotent operation.

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