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

With no annotations, the description carries the full burden. It usefully discloses the paid x402 M2M cost (0.008 USDC on Base), the public-only scope, and roughly what the response contains — real behavioral context. It omits rate limits, private-account failure behavior, pagination, and what errors look like, which matters for a network scraper.

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?

Front-loaded with a templated Trigger/Input/Output breakdown that is easy to scan and free of filler. The structure is slightly formulaic and the Output clause is thin, but every sentence 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?

For a two-parameter tool with no output schema and no annotations, the description covers trigger, inputs, defaults, output shape, and cost. It does not clarify that 'username' is effectively required despite the schema listing zero required parameters, which is the one remaining gap.

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%, so the baseline is 3, but the description adds a genuinely new fact not present in the schema: 'limit' defaults to 10. That default changes call behavior and is worth the bump; beyond it there is no syntax or format guidance for the handle.

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+resource ('Instagram Profile & Media Scraper') and enumerates what it retrieves: public account data, bios, follower statistics, and recent reel engagement. An agent can separate it from instagram_poster (write) and from the non-Instagram scrapers in the sibling list without opening any schema.

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 'Trigger:' clause gives an explicit when-to-use condition tied to needing public Instagram account data. It does not name exclusions or point to an alternative (e.g., when to prefer instagram_poster or a general crawler), so it falls just short of the top band.

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