instagram_reels

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful context beyond that: it enumerates the returned fields (play counts, likes, comments, captions, video URLs), notes cursor-based pagination, and discloses the cost of 1 credit.

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 short sentences, front-loaded with the core action, then the payload, then pagination and cost. Every sentence earns its place with no 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?

With no output schema, the description usefully enumerates the returned fields and mentions pagination and cost, and the schema fully covers the inputs. The only minor gap is the absence of explicit differentiation from instagram_reels_search, but it is otherwise complete for calling the tool correctly.

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%, so the schema already documents cursor, user_id, and username, including the 'pass this or that' relationship. The description's 'Page with cursor' adds a bit of pagination framing but no details beyond the schema, 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 (Get) and resource (an account's Instagram reels) and clarifies the scope with 'the reels tab of a public account'. It implicitly distinguishes from instagram_reels_search by scoping to a specific account, but 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?

Usage is implied by 'an account's reels' and 'reels tab', which tells the agent this is per-account retrieval. However, it gives no explicit when-to-use guidance and does not route the agent away from the similarly named instagram_reels_search.

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