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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds one genuinely new trait — that ship_count appears per POI only when a ship scanner is fitted — but says nothing about scope limits, pagination, or whether the chart reflects only personally visited systems.

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 tight sentences with the core purpose front-loaded and no filler. The scanner note is a legitimate qualifier rather than padding, though the phrasing ('charted POIs and connections') is slightly compressed.

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 still sketches the return shape (POIs, connections, conditional ship_count), which is enough for an agent to know what it receives from this simple read tool. Missing only edge behaviour such as empty/unscanned systems.

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?

Only one parameter (session_id) and schema coverage is 100%, so the schema already documents it fully. The description adds no syntax, format, or sourcing detail about the session ID, making the baseline 3 correct.

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 ('Get your current system's chart') and enumerates the content ('charted POIs and connections'), which separates it from neighbors like get_map, get_poi and get_nearby. It does not explicitly name those siblings, so the differentiation is implied rather than stated.

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?

There is no when-to-use guidance, no mention of prerequisites such as needing to be undocked or having scanned, and no routing to alternatives like get_map or survey_system. The only conditional ('with a ship scanner') describes output content, not when to call the tool.

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