Add Link In Bio Link

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

Goes well beyond the annotations (readOnly=false, destructive=false, idempotent=false): it discloses default placement, the return value (the new link with its `id`), that paid-only fields fail with FEATURE_NOT_IN_PLAN and nothing is saved, and enumerates concrete errors (LINK_LIMIT_REACHED at 50 free / 1000 paid, DUPLICATE_LINK on matching title+URL). The 'nothing is saved' guarantee on failure is exactly the kind of side-effect clarity a mutation tool needs.

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?

Four short sentences, front-loaded with the action and followed by placement default, return value, plan gating, and error codes. No filler, and the most decision-relevant facts (what it does, where it lands, what comes back) come first.

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 an 11-parameter mutation with no output schema, the description covers what an agent needs: creation semantics, default position, return shape, paid-plan failure behavior with no partial save, and the two likely error codes. Annotations are thin, but the description carries the remaining behavioral burden.

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% and the schema already documents each field including paid-plan restrictions, so the baseline is 3. The description reinforces semantics (placement default, which fields are paid-only, that the result carries an `id`) but adds little detail the schema does not already state.

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 (Add) and resource (link, featured link, or category heading on a Link in Bio page), which cleanly separates it from sibling mutators like edit_link_in_bio_link, delete_link_in_bio_link, and reorder_link_in_bio_links. It stops short of naming those siblings explicitly, so the differentiation is implied rather than spelled out.

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 context is implied by the add-to-page framing and the default-placement note ('goes to the bottom unless position: top'), but there is no explicit guidance such as 'use edit_link_in_bio_link to change an existing link' or 'use reorder_link_in_bio_links to move it afterward'. The paid-plan gating and duplication rules are useful conditions but they are constraints, not routing guidance.

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