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

Annotations only cover safety hints (non-readonly, non-idempotent); the description supplies the substantive traits: secret returned once and only a hash stored, no expiry, no revoke path, a 20-mints-per-client-per-day cap yielding key_mint_limit, invalid_api_key for unknown values, and that minting is free. Far exceeds the annotation bar.

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 action and its purpose, then rules, then return shape, then edge cases – a sensible ordering. It is long for a one-parameter tool and repeats 'keys do not expire' from the schema, costing a point on economy.

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?

Despite no output schema, the description enumerates the returned fields (api_key, key_id, key_prefix, label, tier, daily_limit, created_at, note) and covers auth transport, error codes, and the mint rate limit. Nothing needed to call or interpret the tool 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% on the single optional label param, so baseline is 3. The description goes slightly beyond by clarifying what label is not – no cap, no scope, no expiry – which pre-empts a plausible misuse of label as a quota control.

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 ('Mint one free sg_live_ key') and immediately frames the effect on siblings score_spend and get_quota. An agent can distinguish this from get_quota (read remaining scores) and score_spend without opening any 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?

Explicit when-to-use ('Call once per agent when you will score often and have no stored key') and three explicit when-not-to conditions (not every turn, not if a secret is stored, not to read remaining scores – use get_quota). The alternative tool is named with the condition that selects it.

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