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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=false, so safety is largely covered. The description adds real value by disclosing that patches are validated and that the unsaved-card path does not persist, but it says nothing about what happens on validation failure, whether edits are revertible via revert_recipe_edit, or how editId/requestId/reason affect retry behavior. The 'does not modify the library' line slightly softens the destructive hint, which an agent should not read as 'safe'.

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, front-loaded with the action, then the two calling modes, then the scope exclusion. No filler, though "edit an unsaved card without persistence" is compressed to the point of ambiguity about what 'card' means.

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?

An output schema exists, so return values need not be explained. But for a destructive, non-idempotent tool with seven parameters, a ten-variant patch union and nested recipe structures, the description covers only the target selection and omits the patch vocabulary entirely, leaving an agent unable to construct a valid call from the description alone.

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 0% across 7 parameters and a deeply nested patch union of ten variants, yet the description only explains two parameters (recipeId and recipe) and their source. Nothing is said about patches, the ten patch type constants, editId, reason, requestId, editLabel, sessionId, reply, or measurementSystem. This is the highest-leverage information the description could have supplied and it is absent.

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?

"Validate and apply explicit edits" gives a specific verb pair and resource, and the two-mode routing (recipeId vs. full recipe payload) makes the operation concrete. It implicitly separates itself from update_recipe by stating it does not touch the saved library recipe, though it never names that sibling explicitly.

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?

Explicit when-to-use routing: recipeId for a persisted cooking session, or the payload from display_recipe for an unsaved card. The negative case ("Does NOT modify the saved recipe in your library") steers library edits elsewhere, but the description never names update_recipe as the alternative or states prerequisites such as needing an active session.

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