run_yc_companies

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

With no annotations, the description carries the full burden. It does disclose the pricing model ('Flat 5 points per successful run') and the shape of the returned record, which is genuinely useful context. However, it says nothing about authentication requirements, error/failure behavior (e.g., unknown slug), or rate limits, leaving meaningful behavioral gaps.

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 sentences, both front-loaded and functional: the first defines inputs and outputs, the second states cost. The long comma-separated field list is justified because no output schema exists, though it makes the first sentence dense.

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 only one parameter, full schema coverage, and no output schema, the description compensates well by enumerating the returned fields (one-liner, description, batch, status, founders with bios, news, Launch YC posts) and the cost. Only the absence of discovery guidance and failure behavior keeps it from a 5.

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 the single parameter already documents 'Company slug or Y Combinator URL. e.g. airbnb'. The description only restates this ('by slug or URL'), adding no format, normalization, or fallback guidance. Baseline 3 is appropriate.

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 specific verb and resource ('Get one Y Combinator company') plus the lookup keys ('by slug or URL'), which implicitly separates it from the singular-vs-list sibling run_yc_companies_search. It also enumerates the returned fields, making the tool's scope unambiguous. It stops short of naming the alternative tool, so it earns a 4 rather than 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?

Usage is only implied: the agent can infer 'use this when you already have a slug or YC URL, otherwise search first.' There is no explicit when-to-use statement, no pointer to run_yc_companies_search for discovery, and no prerequisites or exclusions. Adequate but with clear gaps.

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