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

Adds real behavioral context beyond the annotations: private accounts return a public shell with `isPrivate: true` instead of erroring, so the agent knows not to retry or treat it as failure, and the 1-credit cost is disclosed upfront. No rate-limit or latency behavior is described, keeping it short of 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?

Four short sentences, front-loaded with the purpose and then the private-account caveat and cost. The opening 'Profile details.' largely restates the title and is the only wasted line.

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 correctly compensates by listing the returned fields and describing the private-account edge case, which is the highest-risk ambiguity for this tool. The only material gap is guidance on the cache parameter.

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 description says nothing about parameters; the required `handle` is fully documented in the schema (username or full URL) but the second parameter, `cache_max_age`, is undocumented in both schema and description, leaving cache/TTL behavior entirely opaque at 50% coverage.

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?

Names a specific resource (an Instagram account's public profile) and enumerates the returned fields: followers, following, post count, bio, links, business category. That is far more informative than the title, though it never explicitly distinguishes itself from close siblings like instagram_profilePostCount or instagram_profileSearch.

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 only implied — 'Public profile for an Instagram account' tells the agent what it fetches, but there is no statement of when to prefer this over instagram_profileSearch, instagram_userEmbed, or instagram_profilePostCount, and no prerequisites or exclusions are given.

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