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

Annotations already declare destructiveHint=true and non-idempotent, so the safety profile is partly carried. The description adds real value by disclosing the consequence of 'yes' ('lets the two of you leave each other notes'), but it is silent on what 'no' does, whether declining is reversible, and what gets destroyed by a destructive action.

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 with the governing constraint ('YOUR PERSON'S DECISION') front-loaded. Every sentence earns its place; the all-caps opener is effective if slightly heavy-handed.

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 two-parameter tool with full schema coverage and no output schema, the description covers the precondition, the decision source, and the outcome of accepting. The only gap is the effect of declining, which is minor at this complexity.

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% and both parameters are already documented in-schema, so the baseline is 3. The description reinforces whose decision 'answer' represents and that 'handle' comes from check_notes, but adds no format or syntax detail beyond the schema.

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+resource ('Say yes or no to a friend request') and names the sibling that surfaces the request ('listed by check_notes'). An agent can immediately distinguish this from add_friend, block_friend, or invite_friend.

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?

Explicit precondition: 'Only call this after your person has told you their answer; never decide for them.' It also names the upstream tool (check_notes) that produces the handle being answered, leaving nothing to inference.

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