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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds behavior the annotations do not: results are sorted newest-change-first and filters are AND'd, both of which affect how results must be read. It does not cover pagination or the api_pass/retry_key operational implications, keeping it short of a 5.

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 short sentences with the scope and sort order front-loaded. The casou=0 concept is explained twice, which is mild redundancy, but overall the text is tight and every sentence carries usable information.

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 7-parameter read-only search with full schema coverage and no output schema, the description supplies what the schema cannot: result ordering, filter conjunction semantics, and the interpretation of the casou=0 slice. Nothing an agent needs in order to call this correctly 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% (every parameter, including the casou enum and the fonte/estado enums, is documented in the schema), so the baseline is 3. The description restates the meaning of casou ('what the indexes know and the catalog does not') and the AND-combination rule, adding only marginal semantics beyond the schema.

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 gives a concrete verb and resource: 'Browse what independent MCP indexes measured,' and scopes it to servers 'this catalog does not list yet (casou=0).' This distinguishes it reasonably well from catalog-listing siblings, but it never explicitly names an alternative tool, so an agent must infer the boundary against mcp_index_signals or index_stats.

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?

Usage is implied rather than stated: 'the list to look at before submitting a server' suggests a pre-submission workflow, and casou=0 is flagged as the relevant slice. However, there is no explicit when-to-use/when-not guidance and no named alternative such as mcp_index_signals or index_stats, so the agent has to guess which sibling to reach for.

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