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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: the data source is satellite altimetry, results include target id and country, and water bodies are classified as natural lake or managed reservoir. No contradiction with 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?

Two sentences with no filler. The first sentence front-loads the purpose and return value, and the second sentence provides the usage context. Every clause earns its place.

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 low-complexity search tool with two parameters and no output schema, the description is complete: it states what is searched, what is returned, and when to use it. Annotations cover the read-only and idempotent behavior, and the schema covers parameter details. Nothing essential 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%, with both query and limit already documented including examples. The description restates the query semantics in prose ('by name, country or continent') but does not add any new parameter-level detail beyond what the schema already provides. Baseline 3 is appropriate.

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 uses a specific verb and resource: 'Find lakes, seas and reservoirs monitored by satellite altimetry, by name, country or continent.' It also states what is returned (target id, country, natural lake vs managed reservoir), which clearly distinguishes it from the sibling measurement tool lake_water_level.

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 explicitly says 'Use to discover which inland water bodies have level data before asking for measurements,' giving clear context for when to call it. It does not name the alternative tool explicitly, but the phrase 'before asking for measurements' effectively points toward lake_water_level without naming it.

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