list_entities

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

No annotations are provided, so the description carries the full burden. It discloses that search_query does not support wildcards, that default returns lean formatting, and that detailed=True returns all fields. It also notes that to get all entities, leave search_query empty. This is good behavioral context, though it doesn't mention pagination or rate limits, which are not critical for a list operation.

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 well-structured with sections for Args, Returns, Examples, and Best Practices. It is front-loaded with the core purpose and then provides details. It is slightly verbose with the best practices section, but each sentence adds value. The examples are concise and illustrative.

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?

Given the tool's complexity (5 optional parameters, no required ones) and the presence of an output schema, the description is fairly complete. It covers parameter semantics, return format (lean vs detailed), and usage guidance. It could mention the output schema's structure, but the output schema itself provides that. The description adequately prepares the agent for correct invocation.

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%, so the description must compensate. It explains each parameter's purpose: domain, search_query (with wildcard note), limit (default 100), fields, and detailed. It also provides examples showing parameter combinations. This adds significant meaning beyond the schema, though it could be more explicit about the fields parameter's format.

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: 'Get a list of Home Assistant entities with optional filtering.' It specifies the resource (Home Assistant entities) and the action (list), and distinguishes it from siblings like search_entities_tool and domain_summary_tool by mentioning filtering and domain overviews.

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 provides explicit usage guidance: it includes best practices such as 'Prefer domain filtering over no filtering' and 'For domain overviews, use domain_summary_tool instead of list_entities.' It also explains when to use detailed=True and how to get all entities, which helps the agent choose between this and alternatives.

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