Add a media to a project's favourites

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

Annotations already declare destructiveHint=false, idempotentHint=true and openWorldHint=false, so "adding it again changes nothing" largely echoes idempotentHint rather than adding new information. The description says nothing about ownership requirements, what happens if the media or project is invalid, or what 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?

One compact sentence with the trigger condition front-loaded and no duplicated content. The analogy is short and pays for itself by clarifying the semantic, though the later clause overlaps with the annotations.

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 three-parameter, all-required, non-destructive toggle with full schema coverage and annotations covering safety and idempotency, very little more is needed. Missing only failure modes (unknown project/media) and any note on the resulting state, which are minor for this tool.

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%: id, mediaId and requestId are each documented in the schema, including requestId's deduplication contract. The description adds no parameter-level detail beyond the prose, so baseline 3 applies.

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: marks a catalogue media as a favourite of a given project. The heart-on-the-web analogy pins the intent precisely. It does not name the paired sibling (unfavourite_media), so it stops short of full differentiation.

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?

"Use this when the user likes a catalogue media for one of their projects" gives a clear activation condition tied to user intent. There is no explicit exclusion or pointer to growwer_unfavourite_media for the reverse action, so the guidance is clear but not complete.

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