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

Annotations already declare readOnlyHint=false, destructiveHint=true, and openWorldHint=true, so the mutation profile is covered. The description adds value beyond them by spelling out which identifier fields are needed per contact type, reducing the chance of a rejected or malformed create. It stops short of warning about duplicate creation despite idempotentHint=false.

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?

A single dense sentence with the write intent and the person/company split front-loaded — no wasted preamble. The trailing 'Clio: POST /contacts.json' endpoint note adds little for an agent and is the only 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 12 parameters but 100% schema coverage and a full annotation set, the description only needs to cover the create semantics, which it does. No output schema exists, yet the 'fields' override parameter is left unexplained in the description — minor, since the schema documents it.

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%, and the schema already documents each field including the person/company distinction for 'name'. The description restates that same person-vs-company mapping for the required fields but adds no syntax, format, or default details beyond the schema, so 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 and resource ('Create a contact') and immediately clarifies the two shapes it can take — person via first_name/last_name, company via name. The 'WRITE:' prefix distinguishes it from the read-oriented siblings like clio_get_contact and clio_list_contacts, though no sibling is named explicitly.

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 conditional guidance for the two input modes (person vs company) and says email/phone are optional, which is useful. But it never says when to prefer this over alternatives such as updating an existing contact or searching first to avoid duplicates, leaving the agent to infer that.

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