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

Annotations already cover read-only, idempotent and non-destructive semantics, so the bar is lower, yet the description still adds provenance the agent needs: the data is a materializer snapshot served verbatim from a stored object with no server-side enrichment. That tells the agent the result is canonical but not freshly computed. It stops short of stating staleness windows or refresh behavior.

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?

Three tight sentences, no padding, with the core action front-loaded. The middle sentence about R2 sibling objects is implementation detail that helps less than the space it occupies, but nothing is redundant or bloated.

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 an output schema, full parameter coverage and annotations, the safety and return-shape burdens are already carried elsewhere, and provenance is covered. The remaining gap is tool selection: a sibling named get_entia_home exists and the description never says how these differ, which is the one thing an agent cannot infer from structured fields.

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%: country, sector, city and slug all carry format/slug examples, and include_render_context documents its own default and the stripping behavior. The description adds nothing beyond the schema, so the baseline 3 applies.

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 verb ('Read') and resource ('materializer snapshot entia.entity_home_projection.v1 for an Entia Home') are specific, and 'claims + projection + policy' clarifies the payload. However, it never distinguishes itself from the near-named sibling get_entia_home, leaving real ambiguity about which home-fetching tool to pick.

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 explicit when-to-use or when-not guidance, and no alternative (e.g. get_entia_home, entity_lookup) is named. The only implied routing cue is 'Same truth as the public ficha HTML/JSON-LD twin — no ad-hoc MCP enrichment,' which hints at canon rather than telling the agent when this is the right call.

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