rebuild_index

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

Annotations (readOnlyHint: false, destructiveHint: false, openWorldHint: true) are already present, but the description adds concrete behavioral details: it takes ~1 minute and makes ~22 requests to an external site. This discloses side effects (network traffic, delay) beyond the annotations without contradicting them.

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 efficient sentences: purpose, when-to-use, and cost. Every sentence adds value and the most important guidance (rarely needed) is front-loaded.

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 zero-parameter, side-effectful maintenance tool, the description covers purpose, usage context, behavior, and cost. The presence of an output schema further reduces the need to explain return values. Nothing essential 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 has zero parameters, so the schema already fully documents this aspect (coverage 100%). No parameter description is needed; the baseline of 4 applies since there's nothing to add.

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 states a specific verb ('Rebuild') and resource ('local URL index from islamqa.org's sitemap'), making the core function clear. It does not explicitly differentiate from siblings like index_status, but the uniqueness is implied given it's a one-off maintenance operation.

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?

Explicitly says 'Rarely needed' and explains the index 'builds itself on first search and refreshes when stale.' This gives clear guidance on when NOT to call it and contrasts with automatic behavior. Also adds cost information (time, requests) that discourages casual use.

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