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

Annotations already disclose the key safety profile: non-read-only, non-destructive, non-idempotent. The description adds only the seller-role requirement. It says nothing about whether a wish can be filled more than once, whether the link is reversible, or what happens to a listing that is already linked elsewhere.

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?

A single short sentence with the actor and action front-loaded and no wasted words. It is arguably too terse for a mutation tool, but there is no padding or redundancy.

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 linking mutation with a fully documented schema and no output schema, the essential calling information is present. What is missing is consequence disclosure – idempotency of the link, reversibility, and whether filling triggers notification to the wisher.

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 100% – both wish_id and listing_id document their format and the tool that produces them. The description adds no syntax or sourcing detail beyond that, so the 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: linking a listing to a wish it fulfils, with the actor scoped to sellers. It is distinguishable from list_wishes and vote_wish, though the jargon 'fill' is only clarified by the secondary clause rather than by naming siblings.

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?

The 'Seller:' prefix implies a role precondition, which is useful context. However, there is no explicit guidance on when to use this versus vote_wish or wish_to_tender, and no statement about when filling is not allowed (already-filled wishes, own wishes, etc.).

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