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

Annotations already cover readOnly/idempotent/closed-world, but the description adds a non-obvious behavioral trait: the two integer id spaces overlap, so a wrong-space id can silently return a different record rather than not_found. That is exactly the kind of failure-mode context annotations cannot convey.

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 what the row contains and the id-space warning comes before any detail. It is a dense, long-sentence description with a heavy parenthetical taxonomy list that could be trimmed without losing meaning.

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?

No output schema exists, and the description enumerates the identity fields returned, so return values are adequately covered. Combined with the id-space warning and the closed-registry framing, an agent has what it needs; only explicit not_found behavior is left implicit.

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% and the schema already says entity_id is not a graph node_id. The description goes beyond that by explaining why the distinction matters (both are whole numbers, id collision returns another record), though it adds no format/range detail.

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: reads one registry row's identity (slug, display name, kind, country, aliases, group memberships) for an entity_id. It immediately distinguishes itself from siblings by naming search_companies and entity_risk_profile as operating in a different id space.

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?

Explicitly says to take entity_id from the registry's own id space and NOT the node_id used by search_companies/entity_risk_profile, naming the alternative tools. It also states the consequence of using the wrong space, which functions as an exclusion rule.

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