check_capacity

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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description aligns with these by describing a read-only check. It adds value by specifying that the tool checks remaining quota, which is not explicitly stated in the annotations. No contradiction exists.

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?

The description is a single, concise sentence that is front-loaded with the main action and includes both parameters. There is no redundancy or extra information, making it efficient and easy to parse.

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?

The tool has an output schema, so return values are handled externally. The description covers the essential scenario (pre-creation check) and is sufficient for a simple tool. It could mention that results may be stale due to openWorldHint, but that is not critical for basic usage.

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?

The description directly explains both parameters: '`count` instances of `flavor`' clarifies that 'count' is the number of instances and 'flavor' is the instance type. Since schema description coverage is 0%, this inline explanation fully compensates and adds meaning beyond the raw 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?

The description clearly states the tool's purpose: 'Check whether `count` instances of `flavor` fit inside the project's remaining quota'. It uses a specific verb (check) and resource (capacity/quota), and explicitly distinguishes from sibling tools like get_quotas by focusing on fit rather than just returning quota values.

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?

The description provides usage context with the phrase 'before attempting to create them', indicating when to use this tool (pre-creation). However, it does not explicitly mention alternatives or when not to use it, though the context is clear enough for an agent to select it appropriately over similar tools.

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