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

Read-only is stated, though it duplicates readOnlyHint=true, so little credit there. The real added value is the disclosed return shape '{ results: [{ id, title, url }] }' and the id-to-fetch workflow, which the agent cannot get from annotations and which matters because there is no output schema.

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 tight clauses: what is searched, what comes back and how to drill down, and the safety profile. Nothing is padded and the search scope is front-loaded.

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 single-parameter read tool with no output schema, the description covers scope, return shape, and the follow-up call, which is close to everything an agent needs. A note on result limits or ordering would make it fully complete.

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% and there is only one parameter, whose description already gives examples ('a product name or a hashtag'), so the baseline of 3 applies. The description adds only that matching is keyword-based against caption and title, which is marginal beyond 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?

The description gives a clear verb (search) plus the searched surface (post caption and title, connected accounts) and the matching mode (by keyword), which is far more specific than the bare tool name 'search'. It does not explicitly contrast itself with siblings like list_recent_posts or get_hashtag_history, so it stops short of a 5.

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?

It routes the agent forward explicitly: 'pass an id to fetch for the full record', naming the sibling fetch and the condition that selects it. It gives no guidance on when to prefer this over list_recent_posts or the hashtag tools, so it is clear context without full alternatives coverage.

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