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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description contributes the returned field inventory, but says nothing about behavior for an unknown slug (error vs empty), pagination of case studies, or cost of the call — moderate additions over annotations, not rich.

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?

One front-loaded sentence with no filler; the identifier requirement precedes the return-value inventory, and 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?

For a single-parameter read tool with annotations covering safety and no output schema, the description supplies an adequate field inventory and slug provenance. Missing only edge-case behavior for invalid slugs, which is a minor gap at this complexity.

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 0% and the single parameter has no schema-level description, so the description must carry the burden. It does explain the slug's provenance ('from search results'), but gives no format, casing, or example, leaving the agent unsure what a valid slug looks like.

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 ('Full Cofounderbase profile for one agency') plus the identifier ('by slug'), and enumerates the returned fields, which implicitly separates it from the list-oriented siblings search_agencies and top_agencies. It does not name those siblings explicitly, so it stops short of 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?

The parenthetical '(from search results)' implies the retrieval workflow after search_agencies, which is useful, but there is no explicit statement of when to call this versus search_agencies or top_agencies and no exclusion guidance. Usage is inferable rather than stated.

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