describe_entity

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses the error behavior (raises a tool error naming known entities) and lists the return contents, which implies it is a read-only operation. It does not explicitly state that it has no side effects, but the 'describe' verb and return of metadata suggest a non-mutating operation. The error message detail is a positive addition.

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?

The description is compact and well-structured. It leads with the core purpose, then lays out args and returns in a clear format, and ends with error behavior. Every sentence adds value; there is no fluff or repetition. The structure makes it easy for an agent to parse quickly.

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?

The description is complete for an entity-description tool. It lists all return components, explains the error behavior, and gives a concrete example. An output schema exists, so detailed return types are not required in the description. Nothing critical is missing for the agent to successfully invoke the tool.

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 0%, so the description must fully explain the 'name' parameter. It does: 'entity name, as returned by list_entities, e.g. "invoices"' — this specifies the value's source, format, and an example. The description adds meaning far beyond the bare schema (which only says 'string'), fully compensating for the lack of schema documentation.

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 clearly states the tool's purpose: 'Describe one entity in full detail' and enumerates exactly what is returned (description, synonyms, source table, primary key, dimensions, facts, filters). This distinguishes it from sibling tools like list_entities (which lists entities) and describe_metric (which describes metrics), making its scope obvious.

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 description implicitly guides usage by specifying that the name should be 'as returned by list_entities', which tells the agent to first list entities to obtain a valid name. It also explains the error behavior for invalid names, which helps the agent handle failure modes. However, it does not explicitly state when to prefer this tool over describe_metric or other siblings, though the resource type (entity vs metric) makes this clear enough.

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