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

Annotations already declare write (readOnlyHint=false), non-destructive, idempotent; the description goes further with the retry semantics ('exact retries return the original receipt even after later replacements'), refusal cases (conflicting keys, self-links, cycles), the immutability of original exports, and the required tickets:write scope. This is substantive 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?

Front-loads what the tool does, then layers semantics, retry behavior, and refusal conditions in tight declarative sentences with no filler. Nothing is redundant with the schema or annotations.

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 6-required-param mutation with no output schema and 0% param coverage, the description supplies preconditions, idempotency behavior, failure modes, and permission scope. The only notable gap is that it does not describe the shape of the returned receipt, which no output schema covers.

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?

With 0% schema description coverage the description must carry the load, and it does for most fields: the required reason, both fetched payload hashes (mapping to expected_source_hash/expected_replacement_hash), and the idempotency key implied by 'use the same key.' It never explicitly disambiguates snapshot_id from replacement_id, leaving the source/target mapping to inference from the surrounding prose.

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 ('Record that one owned saved report replaces another') and immediately scopes it against near-miss interpretations: 'not approval, sharing or a claim of accuracy.' An agent can distinguish this from share/unshare or approval tools without opening the 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?

Gives clear preconditions ('Both reports must have no replacement recorded') and a retry rule ('Use the same key and exact payload after an uncertain response'), which is the main when-to-use guidance for an idempotent mutation. It does not name sibling tools such as get_portfolio_report_lineage or list_portfolio_report_history that an agent might otherwise confuse it with.

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