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

Annotations already cover the safety profile: read-only, non-destructive, open-world. Beyond that, the description adds real value by naming the returned fields (corrected wording, error count, modified flag), disclosing that detailed rule descriptions and offsets are gated behind paid plans, and quoting the 20-credit cost.

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 sentences, front-loaded with the core function and ending with cost. The redundant 'Grammar Check: Grammar Check is...' opening repeats the title and wastes space, but the rest is tight and informative.

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 one-parameter, single-purpose tool with an output schema and clear annotations, the description is essentially complete: input intent, returned fields, tier differences, and cost are all covered. Only input limits and language coverage are unaddressed.

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 100% for the single text parameter and the schema already gives an example, so the baseline is 3. The description adds no constraints such as length limits, language support, or accepted input formats beyond what the schema states.

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 and resource: inspects text for spelling and grammar errors. Clear about what it does, but it does not differentiate itself from the sibling SpellChecker even though it overlaps on spelling, leaving the agent to guess which of the two to pick.

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 usage is implied rather than stated, meaning you supply text that may contain errors. There is no explicit when-to-use versus when-not guidance, and no pointer to SpellChecker or TenseConverter for narrower needs.

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