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

The description explicitly labels this 'the highest-value safe write', but the annotations declare destructiveHint=true. Calling a tool whose annotation marks it destructive a 'safe write' gives the agent a contradicting safety signal, which is the exact failure mode the contradiction rule targets. The otherwise useful details (POST /api/v0/activities, form-encoded, returns { meta, response }) do not offset a direct conflict with the structured hint.

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 short sentences, front-loaded with the mutation and its highest-value use case, then the required target fields, then transport/return details. Every clause earns its place, though the parenthetical '(required)' annotation on target fields is slightly redundant.

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, it covers the key operational facts an agent needs: that it mutates data, the HTTP endpoint and encoding, and the shape of the response. The only real gap is the unresolved safety framing against the destructive annotation.

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 all nine parameters are already documented in the schema; the description only restates that against_type + against_id identify the target and are required. That is a small value-add over the schema rather than meaningful new semantics, matching the baseline 3.

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?

The description states a specific verb (logs/creates) and resource (an activity: note, email, call, meeting) and explicitly names the target concept (against_type/against_id). It is immediately distinguishable from the get_/list_ activity siblings, which read rather than write.

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?

It gives concrete usage context — 'the highest-value safe write — e.g. add a note/comment to a job or company' — which tells the agent when this write is preferable among the create_* family. It stops short of naming explicit alternatives or when-not-to-use conditions, so it is clear but not fully routing.

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