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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful non-annotation context: it is a paid call costing 1 credit, and it discloses the shape of results (hashtags come with post counts, places with location ids). It says nothing about rate limits, pagination, or result caps.

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?

Two short sentences, front-loaded with what is searched followed by the three result types, with the cost placed last as a secondary note. No filler or repetition; every clause carries information.

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 helpfully characterizes the returned result types (accounts, hashtags with post counts, places with location ids) and the cost. It is nearly complete for a one-parameter search tool, though it omits any mention of result limits or pagination behavior an agent might need.

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?

The schema documents q at 100% coverage ('Search text.'), so the baseline is 3. The description adds meaningful semantics beyond that: a single search box that simultaneously matches accounts, hashtags, and places, so the agent knows q is not scoped to one entity type. That is real added value over the terse schema description.

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 (search) and its three target resources (accounts, hashtags, places), which lets an agent distinguish this broad unified search from narrower siblings like instagram_hashtag or instagram_place. It does not, however, explicitly name those siblings as alternatives.

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 'One search box, three result types' — an agent can infer this is the entry-point search for all three entity kinds — but there is no explicit statement of when to prefer it over instagram_hashtag, instagram_place, or instagram_profile, and no exclusions given. The cost note hints at a usage consideration but does not provide routing guidance.

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