instagram_similar

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

Annotations already establish readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely new operational context — the 'Cost: 1 credit' charge — which the agent cannot get from structured fields. It omits result shape and rate-limit behavior, keeping it below a 5.

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 action and the key qualifier (Instagram's own relatedness graph), then cost. The 'Handy for competitor research' line is mild filler but still conveys use context, so it earns most of its space.

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 simple two-param read tool this is nearly adequate, but with no output schema the description should say what comes back (a list of accounts, with handles/ids?) and should clarify that at least one identifier is needed despite required=[] in the schema. Those gaps leave the agent guessing on input contract and return shape.

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% and both parameters are documented in the schema (including the 'pass this or username' relationship and the @/URL flexibility), so the schema carries the load and a 3 baseline is appropriate. The description adds no parameter-level detail beyond the vague 'this one'.

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 and resource ('Find similar Instagram accounts') and clarifies the source of the relationship ('Accounts Instagram considers related to this one'), which separates it from followers/following/profile siblings. It stops short of naming an alternative sibling or restating any sibling's scope, so it is clear but not fully differentiated.

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?

Gives intended scenarios ('competitor research and influencer discovery'), which implies when the tool is useful. However it offers no when-not guidance, no alternatives to compare against (e.g. instagram_search or instagram_profile), and does not note that one of user_id/username must be supplied.

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