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

Annotations only provide readOnlyHint=false, which merely confirms it is a write. The description adds substantive behavior: ingestion is additive and non-destructive, creates new nodes without overwriting or mutating existing records, and requires X-License-Key authentication. These are exactly the traits an agent needs and cannot get from the annotation.

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 sentences, each earning its place: purpose first, then use cases, then exclusions with alternatives, then behavior and auth. Front-loaded with zero redundancy.

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?

An output schema exists, so return values need not be explained. With purpose, selection guidance, additive/non-destructive semantics, and auth requirements all covered, an agent has everything needed to invoke this 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 schema already documents text, family, filename, and space_id. The description echoes the space_id partitioning concept and the verbatim-retrieval implication of family, but adds no format, limit, or default detail beyond the schema. Baseline 3 applies when the schema does the heavy lifting.

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 (stores) plus the resource types (text documents, code snippets, architectural decisions, factual knowledge) and the scoping mechanism (partitioned by space_id). This is clearly distinct from its recall/search siblings named in the same description.

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 explicit when-to-use examples ('saving important facts, project conventions, API keys, user preferences, documentation') and an explicit when-not with named alternatives: icx_recall_scoped for semantic QA, icx_search_facts for keyword lookup, icx_quote_slot for verbatim quotes. Nothing is left to inference.

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