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

Goes well beyond the annotations by disclosing the double-opt-in flow: a confirmation email for a new address, reminders only starting after the link is clicked, and a stop-following link in every reminder. It also explains the beep.me signed-in variant where email is omitted and the follow is immediate with no confirmation. The idempotentHint is consistent with the fact that re-following an already followed team is harmless.

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-loaded with the core action and scope, then layers alternatives, prerequisites, and the confirmation flow in short clauses. Despite the density, every sentence contributes a distinct operational fact, and none is 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 six-parameter mutation tool with no output schema, it covers everything an agent needs: scope, alternative tool, exclusion, email prerequisite, confirmation-email consequence, and the signed-in shortcut. Nothing material about invoking it correctly is missing.

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 the baseline is 3; the description adds instruction-level meaning by telling the agent to collect and never guess the email, and by explaining that matches added or moved later are still covered. The beep.me/omit-email guidance largely restates the schema's own email description, which keeps it below a 5.

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?

Opens with a specific verb and resource: 'Sign the user up for an email reminder before EVERY upcoming match of a football team.' The 'EVERY' scope plus the explicit sibling reference 'for one match, use remind_me' makes it impossible to confuse with remind_me or search_events.

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 concrete trigger phrases ('every match, all matches, whenever <team> plays, or follow <team>'), names the alternative for the single-match case, and states an exclusion ('Only for teams, never for personal appointments'). It also states the prerequisite: ask the user for their email first, never guess.

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