Read PG WAL records

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

Annotations already indicate readOnlyHint=true, so the read-only nature is covered. The description adds value by disclosing the extension requirement and the 'available=false' response if the extension is not installed. This provides operational insight beyond the annotations, though more details about limit behavior or error conditions would strengthen transparency.

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 concise: two sentences that immediately convey purpose, prerequisite, and a key edge case. No redundant information. Front-loaded effectively.

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 has 4 parameters and an output schema, the description covers the core purpose and an important prerequisite/failure scenario. However, it lacks details on parameter usage and expected result format. The output schema likely handles return values, but parameter documentation gaps reduce completeness. It is adequate but not thorough.

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 25% (only the 'database' parameter has a description). The tool description does not explain the meaning or format of key parameters like start_lsn, end_lsn, or limit. It mentions 'LSN range' but provides no details on valid formats or how parameters interact. With low schema coverage, the description should compensate but fails to do so.

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 that the tool reads WAL records over an LSN range, using a specific verb ('Read') and resource ('WAL records'). It distinguishes from sibling tools like get_current_wal_lsn, which gets a single LSN, or read_pg_wal_stats, which reads aggregated stats.

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 clear context: when to use this tool (to read WAL records over an LSN range), and it mentions a critical prerequisite (pg_walinspect extension) and a failure mode (returns available=false). However, it does not explicitly state when not to use this tool or list alternatives, though sibling tools are implied.

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