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

Annotations only carry generic hints (readOnlyHint=false, destructiveHint=false, idempotentHint=false); the description adds genuinely non-obvious behavior — the server mints the import-*/ai-* id and any caller-supplied recipe.id is payload-only, not an upsert key. It does not address duplicate-creation risk or how the new id is returned, which matters given idempotentHint=false and an idempotencyKey parameter.

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-loads the decisive condition in the first sentence, then routes to alternatives and ends with the id caveat. Every sentence carries distinct information, though the opening sentence is compound and could be split for faster scanning.

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 create tool with a deeply nested recipe schema, an output schema, and annotation coverage, the description supplies what structured fields cannot: the save-intent gate and the server-side id minting. Remaining gaps are the source* parameters and what a successful response contains, both partially mitigated by the output schema.

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 only 25%, so the description has to compensate, and it does so for the single most confusing field (recipe.id being ignored as an upsert key). It says nothing about sourceUrl, sourceKind, or how those interact with the recipe payload, leaving three of four parameters undocumented outside the 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?

States a specific verb and resource ('Creates a NEW recipe in your library') and explicitly scopes it against three siblings: display_recipe, update_recipe, and apply_recipe_patches. An agent can pick this tool over the alternatives 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?

Gives an explicit gating condition ('only when the user explicitly asks to save/add it or taps Save') plus the negative case ('a newly generated recipe the user has not chosen to keep, use display_recipe instead'). It also names the correct alternatives for mutation cases (update_recipe, apply_recipe_patches).

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