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

Adds substantial behavior beyond the annotations: the exact refusal errors (recipe_exists on collision, recipe_not_found on unknown name), the guarantee that nothing is overwritten, and that steps and params are preserved. That is exactly the error and data-preservation context annotations alone cannot convey.

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 tight sentences: purpose first, then failure modes, then preservation guarantee. Every sentence carries information and nothing is wasted.

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 two-parameter rename with an output schema and clear safety annotations, the description covers purpose, error semantics, and data preservation. Nothing an agent needs to call it correctly 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%, so the baseline is 3, but the description adds meaning by tying new_name collisions to recipe_exists and unknown name to recipe_not_found. This meaningfully enriches what the schema already documents.

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: 'Renames one of the user's saved recipes.' That is concrete and clearly distinct from recipe_delete, recipe_save, and recipe_list. It doesn't explicitly name a sibling, but the action+resource makes the distinction obvious.

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?

Usage is implied by the tool name and description: use it to change a recipe's name. There is no explicit when-to-use, when-not-to-use, or alternative routing, so guidance is only inferable.

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