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

Annotations already declare readOnly, non-destructive, and non-open-world, so safety is covered. The description adds useful context the annotations do not: it costs no credits and it explains is_locked as plan-gated public faces. It does not disclose pagination behavior or ordering semantics beyond the feed note.

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?

Front-loaded with scope semantics first, then the item shape, then the credit cost, all in three tight sentences with no filler. Slightly dense but every clause carries information an agent would otherwise have to guess.

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 explaining return fields is technically redundant, yet the description's item summary (id, display_name, is_locked, cover) is harmless and helpful for selection. Combined with annotations covering safety and the credit note, an agent has enough to call it correctly; pagination defaults remain only in the schema.

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 baseline is 3. The description earns a bump by expanding the scope enum in domain terms ('mine' default = user's own, 'discover' = public cast, 'feed' = own first then public), which tells the agent more than the terse schema strings. The other three params (page, search, per_page) are left to the schema.

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 (List) and resource (AI influencers), and the scope explanation makes the retrieval model concrete. It does not explicitly distinguish itself from get_character (single-item) or suggest_influencers, so it stops short of full sibling differentiation. An agent can still tell what it returns without opening the schema.

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 three scope values (mine/discover/feed) are explained in plain language, which effectively tells the agent which mode to select for a given intent, including that 'feed' merges own-then-public. No explicit alternatives or exclusions are named (e.g., vs suggest_influencers), so it is clear context without routing guidance.

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