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

Annotations already declare readOnly=false, destructive=true and idempotent=true, so the safety profile is covered. The description adds genuinely new behavior: which KR types reject the write, the audit-log side effect of the note, and the permission scope. It does not say what happens to the prior value, but destructiveHint covers that.

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 tightly packed sentences, purpose front-loaded, required/optional parameters called out inline, and no filler. Every clause carries an actionable constraint.

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 mutation tool with no output schema, the description covers what it does, the rollup exclusion, required params, and authorization. It stops short of describing the success response or what the audit-log entry contains, which is a minor gap given the annotations already flag destructiveness and idempotency.

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 the baseline is 3. The description adds real meaning beyond the schema by clarifying that 'value' is the new current value and that 'note' feeds the audit log, which the schema wording ('explaining the update') does not state.

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 ('Log a progress update on a key result') and immediately scopes it to manual KRs only. The rollup-type restriction makes it unmistakable against adjacent tools like create_key_result or update_goal, without the agent needing to open 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?

Explicitly states when NOT to use it: KRs with TASK_COUNT / TASK_PERCENTAGE rollup are auto-calculated and reject manual writes. It also gives the permission condition ('Any org member except a Guest'). No alternative tool is named for the auto-calculated case, so it falls just short of a 5.

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