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

Annotations declare readOnlyHint=true and destructiveHint=false, yet the description describes mutating operations ('Set: period plus limit_credits' and 'Remove: remove_id') that create and delete spend controls. This directly contradicts the read-only declaration, so an agent trusting the annotations could invoke a state-changing operation believing it is a pure read. The account prerequisite and 80% default alert are useful, but the core safety profile is inconsistent.

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?

Dense but well front-loaded: the capability sentence comes first, then behavior, then the argument-based mode breakdown, then the account requirement. Every sentence carries distinct information and the verb-led fragments ('Set:', 'Remove:') are easy to scan.

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 6-parameter, no-output-schema tool the description covers all three modes, the default alert threshold, what happens when a limit is hit, and the free-account prerequisite. It falls short only on how to read back or clear individual alerts and on the fact that removals are permanent.

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 description coverage is 0%, so the description carries the burden, and it does so well: it groups period + limit_credits as the set payload, marks listing_id and label as optional scope selectors, explains remove_id, and gives alert_pct meaning plus its 80% default. Only the mutual exclusivity of label vs listing_id and any ID formats remain unstated.

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 gives a specific verb and resource (cap spend through StartupHub per day/month, scoped to everything/one listing/one label) and enumerates the three operating modes. It is clear enough to act on, but never names or contrasts the closest sibling, get_my_usage, which also reports credit consumption, so an agent could hesitate between them.

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 explicitly maps arguments to intents: no arguments lists limits and current spend, 'period plus limit_credits' sets one, and 'remove_id' removes one. What's missing is guidance on when to reach for this tool versus get_my_usage or list_credit_packs, and no exclusion conditions are stated.

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