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

Annotations already declare readOnly=false and destructive=false; the description adds meaningful context beyond them: external_key uniqueness causes a 409 refusal, and lat/lng must be sent together. It does not cover permissions or what the response returns, but the core write behavior and failure mode are disclosed.

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 front-loaded sentence that identifies the operation first and then enumerates constraints. It is dense but every clause carries useful information; minor readability cost from cramming all parameters into one sentence.

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 6-parameter write tool with annotations covering safety, the description covers purpose, required name bounds, paired coordinates, and the key duplicate-refusal behavior. Missing is any mention of authentication requirements or the created object's return shape, but the essentials for invoking it are 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 coverage is 67%, so the schema carries much of the parameter documentation. The description adds the 409 consequence for duplicate external_key and reinforces lat/lng pairing, but address and client_company are only named with no added 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 specific verb and resource: 'Create a site (a job location) in the organization.' The parenthetical defines 'site' and the write framing clearly distinguishes it from read siblings like get_site, list_sites, update_site, and link_site.

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 description never says when to choose this tool over alternatives such as list_sites, find, or create_project, nor does it advise checking for an existing site before creating. It provides behavioral constraints (409 on duplicate external_key) but no usage routing.

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