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

Goes beyond the annotations (idempotentHint, destructiveHint=false) by explaining the observable consequences: a same-day repeat changes nothing, and a missed day resets the streak. What it omits is the response shape or error behavior for an invalid token, which matters since there is no output schema.

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, each carrying a distinct operational fact: what it does, the daily cap and idempotent behavior, and the reset rule. No filler and the core action is front-loaded.

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?

Adequate for a two-parameter mutation with full schema coverage: it discloses auth needs, rate-of-use constraint, idempotency effect, and failure consequence. Only the return/error behavior is unspecified, a minor gap given the absent output schema.

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 already document their provenance (slug from /s/<slug>, token from the private check-in link). The description only restates that the token is private, adding no syntax or format detail beyond the schema, so the baseline 3 applies.

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 ('check in') and resource ('Perkadoo Streak Badge today'), plus the auth requirement (private token). This clearly separates it from create_streak_badge and get_streak_badge without the agent needing to inspect schemas.

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?

Establishes the operational context: one check-in per day in the streak's time zone, with the private token. It stops short of explicitly naming alternatives or stating when-not-to-use, but the daily-limit framing tells an agent when a call is meaningful.

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