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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so the safety profile is covered. The description adds meaningful value beyond that: it discloses what the response contains (full stored detail set) and the endpoint's read semantics, which is important since there is no output schema.

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?

A single front-loaded sentence listing the returned fields followed by the endpoint mapping — every element earns its place with no filler.

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 read-only single-record fetch with no output schema, the description covers the return contents well, and safety is handled by annotations while parameters are fully documented in the schema. Only a note on error/not-found behavior or sibling routing is missing.

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%, so both parameters are already documented, including the bg/en enum semantics for language. The mention of 'names in both languages' and 'by id' adds light reinforcement but no syntax or format detail beyond the schema, so baseline 3 applies.

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 ('One client by id') and enumerates the stored details returned (names in both languages, Bulstat, VAT, address, MOL, code, custom properties), plus the underlying endpoint. This clearly separates it from sibling list tools like invbg_list_clients, though no sibling is named explicitly.

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?

'by id' implies you must already know the identifier, and the schema's client_id description points back to invbg_list_clients. However, the description itself gives no explicit when-to-use/when-not guidance or comparison with list/other get tools, leaving usage only implied.

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