instagram_search_posts

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds behavioral context beyond these: it mimics the app's search results tab, uses topic modelling rather than exact hashtags, and explains the purpose of reaching accounts. This adds useful behavioral detail without contradicting the annotations.

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?

The description is fairly concise and well-structured: an intro, a contrast, a use case, then Args and Returns. It front-loads the main action. There is some redundancy in the Args section that repeats schema info, but overall it is organized and not overly verbose.

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?

Given the tool has annotations and an output schema, the description covers the essential aspects: what it does, how it differs from hashtag lookup, the use case, and what it returns. It provides enough information for an agent to decide when to use it and what to expect. The return fields are explicitly listed, and the matching behavior is explained. Nothing critical is missing.

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% with descriptions for both query and amount. The description's Args section merely restates the schema information ('The phrase to search for', 'How many posts to fetch') without adding new semantics. The intro adds a note about matching captions and topic modelling, which indirectly informs query behavior, but not enough to raise above the baseline of 3.

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?

The description states a specific verb and resource: 'Search posts by keyword, the way the app's search results tab does.' It also distinguishes from hashtag lookup, making it clear this is a keyword-based post search. The purpose is unambiguous and differentiates from siblings like instagram_search_users or instagram_get_hashtag_medias.

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 description explicitly contrasts with hashtag lookup: 'Unlike hashtag lookup this matches captions and Instagram's own topic modelling, so it works for phrases nobody tags.' This tells the agent when to prefer this tool. It also states a specific use case: 'Mostly useful as a way to reach the accounts behind the posts.' That is clear guidance on when to use it.

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