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

Annotations already flag destructiveHint=true and readOnlyHint=false, but the description adds the crucial reason: both body and category are required because the backend replaces the full note on update. That tells the agent omitted fields are overwritten, which annotations alone cannot convey. It doesn't cover permissions or error behavior, hence a 4 rather than 5.

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?

Front-loads the most important operational fact (full replacement) in the first two sentences, then the inference rule, then the fallback retrieval. The ten-item category list is long but justified because the schema supplies no enum. Slightly verbose but every block earns its place.

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 destructive mutation with an output schema, the description covers what matters: replacement semantics, the required-field constraint, category inference, ambiguity handling, and UUID retrieval. Return values are handled by the output schema, so no description gap remains.

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 100%, so a baseline of 3 is warranted, but the description goes beyond it: the category mapping effectively defines the value domain as an enum, which the schema lacks (0 params with enums) and explicitly delegates back to the description. It also clarifies the body/category joint requirement. The remaining parameters are left to their schema entries.

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 ('Updates the body or category of an existing job application note') and immediately scopes it against the sibling add_job_application_note by emphasizing 'existing' and the full-replacement semantics. An agent can tell this apart from add/delete/list note tools without opening a 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 explicit procedural guidance: infer category from note content when unstated, ask the user when ambiguous, and call list_job_application_notes first if the UUID is unknown. Both the when-to-use and the prerequisite retrieval step are named.

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