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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavior beyond that: scaling applies only to this answer and is not persisted, which prevents the agent from assuming a write occurred. It stops short of saying what happens if the recipe id is unknown or whether a summary versus full detail is returned.

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?

Two tight sentences, front-loaded with the 'Use this when' trigger, followed by the one non-obvious caveat. Nothing is redundant with the title or the schema, and no sentence could be dropped without losing information.

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, fully annotated read tool with 100% schema description coverage and no output schema, the description supplies the trigger, the shape of the result (ingredients and steps), and the persistence caveat. Nothing an agent needs in order to call it correctly is missing, aside from minor error-behavior detail.

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. The description goes slightly beyond the schema by framing servings as an ephemeral scaling of ingredient quantities that does not alter the saved recipe, which is semantic meaning the schema does not encode. The recipeId parameter's provenance is left to the schema's own description.

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 states a specific verb and resource: fetch the full ingredients and steps of a saved recipe, with optional serving scaling. That is clear enough to distinguish a detail-fetch from write siblings like save_recipe or update_recipe. It does not, however, distinguish itself from the near-identical sibling show_recipe, which leaves a real ambiguity unresolved.

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?

There is an explicit trigger condition ('when you need the full ingredients and steps of one of the user's saved recipes'), which is more than implied usage. But no when-not guidance or named alternatives are given, and the schema mentions search_recipes only in passing for the recipeId parameter. The existence of show_recipe makes the missing differentiation a meaningful gap.

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