List Lines

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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds important non-obvious behavior: sensitive fields are redacted, an alternative tool exists for authorized credential access, and state filtering has a higher cost. These are meaningful additions beyond annotations.

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 four sentences are front-loaded and each carries useful information: returned fields, filters, redaction/alternative path, and state-filter cost. There is no filler or repetition.

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 list tool with no output schema, the description gives the key returned fields, filter surface, redaction behavior and cost caveat. Pagination and ordering are left to the schema descriptions, which is acceptable but leaves some operational detail outside the description.

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 only 40%, and the description compensates by naming the five main filters (msisdn, iccid, userId, type, state) plus the type values local/travel and the state filter cost. However, it does not explain page, maxPages, pageSize, orderBy or orderDirection, leaving half of the parameters without description-level semantics despite the low schema coverage.

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 states a specific verb and resource (list lines/numbers) and enumerates what is returned, including type, state, ICCID and holder. It also distinguishes the credential-viewing path by naming telgea_get_sim_credentials for redacted eSIM/PIN/PUK data, so an agent can tell what this tool covers versus a related one.

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?

It clearly routes credential access to telgea_get_sim_credentials when the caller is allowed, and it warns that filtering by state is costlier than other filters. It does not explicitly contrast with telgea_get_line for single-line retrieval, but the list-versus-get distinction is strongly implied.

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