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

Annotations already declare idempotentHint=false and destructiveHint=false; the description reinforces non-idempotence with a concrete consequence ('calling twice adds the URLs twice') and adds the CONFLICT failure mode plus the return shape `{ job, items_added, items_dispatched }`. That is real context beyond the annotation set.

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?

Four dense sentences, front-loaded with the precondition and vocabulary, then failure modes, then return value. Efficient overall; the mutual-exclusivity restatement slightly duplicates the schema but is defensible as a guardrail.

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 14-parameter mutation tool with no output schema, the description supplies the missing pieces: the open-job precondition, the closed-job failure mode, non-idempotence, and the return shape. An agent has everything needed to invoke it correctly.

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%, so the baseline is 3, but the description adds cross-tool semantics the schema cannot express: the item vocabulary mirrors spicrawl_batch_submit and the shared settings apply only to the newly appended items, clarifying scope of the settings parameters.

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?

Specific verb (append) + resource (URLs to a batch job) with the exact precondition (`open: true`) that distinguishes it from spicrawl_batch_submit. An agent can tell what this does and which sibling it complements without opening a schema.

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?

States the precondition (`open: true`) and the failure condition (CONFLICT if closed/finished), and cross-references spicrawl_batch_submit for the shared item vocabulary. It stops short of naming an explicit alternative for the closed-job case, but the CONFLICT note makes the boundary clear.

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