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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description adds instead of repeats: it takes no arguments, returns no CVE/technique/group/detection data, and yields the same answer to every caller of a given snapshot. It stops short of stating whether there is any cost, caching, or staleness caveat beyond the snapshot framing.

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 definition, then uses labeled blocks ('When to call it', 'What it is not for') so an agent can scan the trigger and the exclusion without reading the enumeration of return fields. No sentence is filler.

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 and no parameters, the description carries the return-value burden itself and does so fully: it names every field returned and the downstream arguments those fields populate. Nothing an agent needs before calling it 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?

The tool takes zero parameters, so the baseline is 4. The description usefully reinforces this ('takes no arguments') and redirects the agent to the metadata it exposes rather than implying any input.

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 ('Describe the graph this server reads') and enumerates exactly what it returns: snapshot id and creation time, schema version, node labels, relationship verbs, contributing sources, and path templates. It is immediately distinguishable from siblings like graph_lookup, which return actual facts.

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?

Gives an explicit trigger ('once at the start of a session'), names the concrete downstream uses (valid label values for graph_lookup/graph_search/graph_neighbors, verb values for graph_neighbors, template names for graph_path, snapshot citation when reporting), and an explicit 'What it is not for' exclusion routing fact-seekers to graph_lookup.

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