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

Annotations already flag destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds genuine context beyond them: partial-update behavior, that tags are replaced and an empty string clears them, and that individualID is returned. It doesn't explain permission requirements or irreversible effects of tag-clearing beyond the hint, so a 4.

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 cluster with the WRITE marker and entity front-loaded, followed by the field-level caveats and the return value. No filler; every clause conveys a distinct behavioral fact.

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 15-parameter mutation with no output schema, the description covers the essentials: partial-update semantics, the tag-replacement edge case, a scope exclusion, and the return value (individualID). Minor gaps remain around permissions and custom_fields handling, but those are partly covered in the schema itself.

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 only 40% across 15 parameters, so the description must compensate and only partly does. 'Fields you leave out are not sent' is valuable patch-semantics guidance absent from the schema, but the majority of parameters (email, phones, gender, birth_date, group_id, servicing_agent_id) get no added meaning.

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?

Opens with an explicit verb and resource ('WRITE: change fields of an existing individual') and the word 'existing' cleanly separates it from agencybloc_create_individual. The endpoint is also stated, removing any ambiguity about what is being modified.

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?

Establishes when/how to use it via partial-update semantics ('fields you leave out are not sent') and a clear exclusion ('Addresses are not changed here'). It stops short of naming a specific sibling tool for address changes or noting prerequisites, so it falls just under a 5.

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