route

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description goes beyond by enumerating returned metrics (length, straight-line length, narrowest width, highest step, waypoints, image) and disclosing error behavior ('if the points are in different regions it says so and why').

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-loads the core purpose, then return values, then the min_width use case, then failure behavior. Sentences are dense with facts and none is filler, though the return-value enumeration makes it dense rather than tight.

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?

With no output schema, the description usefully enumerates what the tool returns, which is a real contribution. But for a 9-parameter navigation tool with 0% schema coverage, it omits the meaning of most tunable parameters (agent size, slope/step limits), leaving the definition only partially complete.

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 0%, so the description must carry parameter meaning, and it only explains min_width. Eight parameters (cell, names, max_step, agent_height, agent_radius, max_slope_deg, and even start/end beyond 'two world points') carry no meaning anywhere, including the navigation constraints that define walkability.

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 with scope: 'Shortest walkable route between two world points.' This immediately distinguishes it from siblings like line_of_sight, walkable_map, and check_passages.

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 gives one concrete use case for min_width ('can a group or a wide vehicle go from A to B?'), which is helpful context. However it never explicitly routes the agent between alternatives (line_of_sight, check_passages, walkable_map) or states when not to use it, leaving sibling selection to inference.

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